1. Field of the Invention
The present invention relates to a method of controlling interference between multi-cells in a random access network, and more particularly, to a technical idea of accessing a beamforming and a channel based on channel information obtained in a distributed manner in the random access network.
2. Description of the Related Art
Since users increasingly converge on a small space and mobile data traffic is gradually increasing, extensive interference among the users in a wireless communication network may be generated. Accordingly, an effective communication by the users may place a high priority on controlling an interference that degrades a network performance. A channel in which the interference among the users is present may be referred to as an interference channel. The simplest method of removing the interference from the interference channel is the users utilizing limited communication resources without sharing, for example, a time, a frequency, and an antenna. A time division multiple access (TDMA) to divide and use a time, or a frequency division multiple access (FDMA) to divide and use a frequency may be included in the foregoing method. However, since the method supports communication for a single user at a time, spectral efficiency is substantially low. Thus, multiple users may need to simultaneously use the communication resources in order to enhance system performance. Conducting research on interference channels and finding an optimal interference control scheme may be significant to enhance efficiency in communication.
Recently, based on an information theory, a new scheme, for example, an interference alignment (IA), may obtain a multiplexing gain enhanced when compared to conventional technology. In a case of a current IA scheme, issues, such as a calculation complexity required for each terminal and information on a wireless channel to be provided in advance may occur in practice.
Accordingly, to implement the IA scheme in an actual system, signaling overhead among geometrically increasing nodes may be required. The requirement of signaling overhead may be a greatest factor hindering actual implementation. Therefore, technology for solving an issue of the requirement of signaling overhead and maximizing a performance gain of the IA in a random access network may be required.
Recently, in a cellular system, an opportunistic interference alignment (OIA) scheme to reduce the signaling overhead is proposed. Through the OIA scheme, beamforming may be implemented to allow users to minimize interference in another cell based on restricted channel information and thus, a base station may be allowed to select a user corresponding to a least amount of interference in another cell, in a cell of the base station. The selection may be available in the cellular system. However, a direct application of the OIA may have an issue since a centralized controller, such as a base station, is not a basic element of the random access system.